the trouble usually come from the miss matched normals (when you stitch in the geometry this is not an issue) at the seam. for example.... the cyinder on the right has the normals at the seam edited to be the same as the plane.
I tried to use Sampler few times through years and never found it any helpful really . Uninstalled it to save space. Just read it got some new AI upscale and photo to material . Is it worth a new try? Any better than before. Something that could take 2x2 meters megascan material and turn it into covering 10 meters long…